# MSG_VEL_STD_DEV
该数据包用于描述：卡尔曼滤波P矩阵的速度标准差
| Packet ID | 0x55 | ||||
|---|---|---|---|---|---|
| Length | 12 | ||||
| Read / Write | Read | ||||
| Offset | Size | Format | Field | Unit | Description |
| 0 | 4 | float32_t | Velocity_north_standard_deviation | m/s | 北向速度的标准差 |
| 4 | 4 | float32_t | Velocity_east_standard_deviation | m/s | 东向速度的标准差 |
| 8 | 4 | float32_t | Velocity_down_standard_deviation | m/s | 地向速度的标准差 |